In IPF patients and animal models of pulmonary fibrosis, a significant and sustained inflammatory response characterized by the infiltrations of inflammatory cells were observed and the increased expression of inflammatory mediators, including TNF-α, TGF-β1, IL-1, inducible nitric oxide synthase (iNOS), and interferon (IFN)-γ were detected [27–32]. Here, NOS2 is linked to pulmonary fibrosis.